Understanding Unbroken Line

Hello!

I'm somewhat confused about whether my family line is broken or unbroken per the current understanding, and was hoping that someone could help me clarify.

My GF and GM were born in Italy to Italian families and emigrated to North America in the 1950s, where they had my M. Both had their Italian citizenship when my M was born.

My GF passed away in the 1970s, before I was born. He never renounced his Italian citizenship or obtained additional citizenship. After his death, my GM gave up her Italian citizenship.

My M never obtained Italian citizenship, but I believe would have qualified for it through my GF.

Would my siblings and I still qualify or is our line broken? Any insight would be great, thanks for the help!